JPH103605A - Manufacture of magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a magnetic head capable of suppressing an effect due to adjacent cross talk with excellent processing yield. SOLUTION: Positioning projection parts 25A, 25B, 26A, 26B whose both side surfaces are nearly vertical to the track width control groove forming surface are formed when a track width control groove is formed. Then, by positioning these positioning projection parts each other (25A and 25B, 26A and 26B), magnetic gap forming projecting parts 24A of respective magnetic core half bodies are positioned each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a magnetic head suitable for mounting on a magnetic recording / reproducing apparatus capable of high-density recording, such as a video tape recorder (VTR) or a digital audio tape recorder (R-DAT). About.

[0002]

2. Description of the Related Art For example, in order to perform high-density recording,
It is necessary to make the track pattern recorded on the magnetic recording medium as narrow as possible. As one method, recording without providing a guard band between tracks,
There is a so-called guard bandless recording method. In such a recording method, the recording density can be improved because there is no guard band.

However, in this guard bandless recording system, since there is no guard band between each track, so-called adjacent crosstalk which occurs when a magnetic head traces (reproduces) a signal of an adjacent recording track is problematic. Becomes

[0004] This will be described with reference to a magnetic head mounted on a home VTR. As shown in FIG. 1, in this magnetic head, recording and reproduction are usually used for both purposes. To ensure this, the head width (gap width) HW of the reproducing head is formed wider than the recording track pitch.

Therefore, when a recording pattern having no guard band is reproduced by the magnetic head mounted on the home VTR, the recording track T adjacent to the track TA where the gap G1 in which the magnetic gap has shifted is found.
The signal of B is picked up, and the adjacent crosstalk occurs.

[0006]

By the way, in a conventional magnetic head, for example, in the case of a home digital VTR, when an azimuth-recorded signal is reproduced, even if the reproduction C / N is fixed, an error is obtained. There is a variation of about ± 1 digit in the rate, and a magnetic recording / reproducing apparatus such as a home digital VTR equipped with a magnetic head must be designed with a lower limit of the variation.

In a conventional magnetic head, for example, in a long-time recording in which the standard tape feed speed of a home VTR is set to 2/3 and the recording / reproduction time is increased by 1.5 times,
There was a problem that an error rate sufficient for reproduction could not be obtained due to insufficient C / N.

On the other hand, when the track pitch, which is the pitch of the pattern recorded on the magnetic tape, becomes narrower with the increase in the recording density, the influence of the adjacent crosstalk increases, and the S / N and the error rate are degraded. It is known that

For this reason, in the conventional magnetic head, in order to minimize the influence of adjacent crosstalk during reproduction, the angle of the track width regulating groove is formed so as to be substantially perpendicular to the surface facing the magnetic gap. Can be considered.

However, the magnetic head having such a shape has a small cross-sectional area of the magnetic core near the magnetic gap, which is not preferable in terms of recording and reproduction.

Further, a conventional method for manufacturing a magnetic head includes:
The projections for forming the magnetic gap of the pair of magnetic core halves are not completely aligned and butted to both ends, and the ends of the projections for forming the magnetic gap of the pair of magnetic core halves are displaced. It is known that adjacent crosstalk is caused by this shift, but the relationship between the shift and adjacent crosstalk is not specifically clarified.

For this reason, for example, by forming the track width regulating groove at a large angle, that is, by forming the track width regulating groove into a V-shaped groove having a large angle, both ends of the magnetic gap forming projections of the pair of magnetic core halves can be formed. As long as they match.

However, when the angle of the track width regulating groove is increased, the conventional magnetic head manufacturing method performs the work of abutting the magnetic gap only at the edge of the track width regulating groove. Had.

Therefore, the present invention has been proposed in view of the above-mentioned conventional technical problems, and is intended to manufacture a magnetic head capable of reducing the influence of adjacent crosstalk with a high processing yield. It is an object to provide a method.

[0015]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, the influence of adjacent crosstalk has been reduced by restricting the amount and direction of the track width of the magnetic gap. In addition to finding that the magnetic gap can be suppressed to a small value, the present inventors have found a method of manufacturing a magnetic head in which the deviation amount and the direction of the track width of the magnetic gap are constant.

That is, the present inventors obtained the experimental results shown in FIGS. 4 and 5, and studied the experimental results in detail, and completed the invention capable of realizing the operation and effect described later.

First, as a case where the magnetic gap is shifted, as shown in FIG. 3, the direction of the center line F caused by the shift of the ends of the magnetic gap forming projections of the pair of magnetic core halves is changed. A case where the direction becomes closer to the azimuth angle of the recording track TB adjacent to the desired recording track TA;
As shown in FIG. 2, the direction of the center line F generated by the displacement of the ends of the magnetic gap forming projections of the pair of magnetic core halves is the direction in which the azimuth angle of the recording track TA and the recording track TB adjacent to the recording track TA become farther. Is divided into

That is, the relationship between the direction F of the bisector of the opening angle θ due to the displacement G1 of the magnetic gap g and the angle of azimuth recording of an adjacent recording track is taken into consideration.
The case of FIG. 2 is referred to as “a deviation of the magnetic gap in the + direction”, and the case of FIG. 3 is referred to as “a deviation of the magnetic gap in the − direction”.

In the portion G2 where the head width (gap width) HW of the reproducing head extends over the adjacent recording track TB, the track T determined by the regular magnetic gap is used.
The signal of A is picked up, and the signal of the adjacent recording track TB is not picked up for scanning the so-called reverse azimuth.

Therefore, when the influence of adjacent crosstalk in both cases is examined, it can be seen that the influence of adjacent crosstalk is small as shown in FIG. On the other hand, when the magnetic gap is shifted in the negative direction, as shown in FIG. 5, it can be seen that the influence of the adjacent crosstalk is large.

Here, FIGS. 4 and 5 are characteristic diagrams showing how the error rate changes due to adjacent crosstalk in the case where the magnetic gap is displaced. FIGS. 4 and 5 show the case where the azimuth angle of the magnetic head is ± 20 °. The plots (vertical lines) shown in FIGS. 4 and 5 are the results of measuring the influence of adjacent crosstalk with “present” and “absent”. It is a plot, and the upper part of the vertical line is a plot of a portion affected by crosstalk. One line indicates data of one magnetic head.

By the way, the adjacent pattern components picked up by the regular magnetic gap g can suppress the high frequency part due to the azimuth loss. Loss can hardly be expected. actually,
In a high frequency part, there is a case where it is about 5 dB higher than the amount picked up from the regular magnetic gap. Therefore, for example, in a system in which low-frequency components are not used for signal detection, such as a signal of a partial response class 4, such leakage from a relatively high frequency adjacent track has a considerable effect on signal detection. Will be.

From the above results, it is sufficient to manufacture the magnetic head so that the magnetic gap is shifted in the + direction or to manufacture the magnetic gap so that the magnetic gap is not shifted. According to the method, when the magnetic gap abutment operation is performed while the direction of the magnetic gap deviation is kept constant, it is difficult to control the amount of deviation of the magnetic gap in the track width direction, and it is not possible to maintain high track accuracy.

In order to solve the above-mentioned problems, a method of manufacturing a magnetic head according to the present invention includes a method of forming a pair of magnetic core halves each having a track width regulating groove and a magnetic gap forming projection formed thereon. In a method for manufacturing a magnetic head, wherein a width regulating groove forming surface is abutted and joined so as to face each other, and a magnetic gap is formed between abutting surfaces of the magnetic gap forming projections, both side surfaces are formed when the track width regulating groove is formed. Form a positioning projection that is substantially perpendicular to the track width regulating groove forming surface, and align these positioning projections to form a magnetic gap forming projection of each magnetic core half. The parts are aligned with each other.

According to the method of manufacturing a magnetic head of the present invention,
Each of the magnetic cores is formed by forming a positioning projection having both sides substantially perpendicular to the track width regulating groove forming surface when the track width regulating groove is formed, and aligning these positioning projections. Since the half magnetic gap forming projections are aligned with each other, a highly accurate magnetic head is manufactured.

Also, a plurality of positioning projections having different butting widths are formed at a constant pitch, and the positioning projections having different butting widths are aligned to form a magnetic gap of each magnetic core half. By providing a displacement corresponding to the difference in the width of the positioning projection to the butting position of the projection, a magnetic head having a constant displacement of the magnetic gap can be manufactured with good butting accuracy.

When the azimuth angle is given to the magnetic gap, the center line between the abutting surface of the magnetic gap forming protrusion and the wall surface of the track width regulating groove facing the abutting surface,
The angle between the azimuth direction of adjacent recording tracks
A magnetic head capable of suppressing crosstalk from an adjacent channel at the time of reproduction is provided by giving a deviation so as to be larger than an angle between a magnetic gap and the azimuth direction of the adjacent recording track. .

[0028]

Embodiments of the present invention will be described below in detail with reference to the drawings.

Embodiment 1 In this embodiment, a magnetic gap portion is formed by a metal magnetic film.
This is applied to an in-gap) type magnetic head (hereinafter, referred to as “MIG head”).

As shown in FIG. 6, the magnetic head of this embodiment has
A closed magnetic path is formed by a pair of magnetic core halves 5 and 6 including ferrite magnetic core substrates 1 and 2 and metal magnetic films 3 and 4 respectively formed on butted surfaces of the magnetic core substrates 1 and 2. A magnetic gap g provided with an azimuth angle is formed between the butting surfaces of the metal magnetic films 3 and 4 and operates as a recording / reproducing gap.

The magnetic core substrates 1 and 2 are made of an oxide magnetic material such as ferrite, and function as auxiliary cores for backing up the metal magnetic films 3 and 4 having a small core cross-sectional area functioning as a main core. ing. That is, since the core cross-sectional area of the metal magnetic films 3 and 4 is small, deterioration of the reproduction output is prevented by the core volumes of the magnetic core substrates 1 and 2.

Further, in the magnetic core substrates 1 and 2, the shape on the abutting surface side is formed to have a substantially trapezoidal cross section. That is, the abutting surfaces of the magnetic core substrates 1 and 2 have the gap forming surfaces 7 and 8 parallel to the magnetic gap g and the track width Tw of the magnetic gap g at both ends of the gap forming surfaces 7 and 8. Track width regulating grooves 9, 10, 11, 12 for regulating are formed.

The track width regulating grooves 7, 8, 9,
A non-magnetic material 14 such as glass is filled in each of the layers 10 for the purpose of securing the contact characteristics with the magnetic recording medium and preventing uneven wear due to sliding contact.

In addition, the depth of the magnetic gap g is restricted on the abutting surface of one magnetic core substrate 1.
A winding groove 13 having a substantially U-shaped cross section for winding a coil (not shown) is formed in the core thickness direction.

On the other hand, the metal magnetic films 3 and 4 are formed on the butted surfaces of the magnetic core substrates 1 and 2 from the front side to the back side. That is, the metal magnetic film 3,
Reference numerals 4 denote gap forming surfaces 7 and 8 of the magnetic core substrates 1 and 2 and track width regulating grooves 9 and 10 provided on both end sides thereof.
It is formed on 11 and 12 from the front side to the back side.

For the metal magnetic films 3 and 4, a ferromagnetic material having a high saturation magnetic flux density and excellent soft magnetic properties is used. , Non-crystalline or microcrystalline ones can be used.

For example, Fe—Al—Si alloy (Sendust), Fe—Si—Co alloy, Fe—Ni
Alloy, Fe-Al-Ge alloy, Fe-Ga-Ge alloy, Fe-Si-Ge alloy, Fe-Si-Ga alloy, Fe-Si-Ga-Ru alloy, Fe-Co-Si
-Al alloys and the like. In order to further improve corrosion resistance, wear resistance, etc., Ti, Cr, Mn, Z
r, Nb, Mo, Ta, W, Ru, Os, Rh, Ir,
At least one of Re, Ni, Pd, Pt, Hf, V and the like may be added. Also, oxygen-containing sendust, nitrogen-containing sendust, oxygen-containing Fe—Si—Ga
A crystalline magnetic film such as a -Ru alloy or a nitrogen-containing Fe-Si-Ga-Ru alloy may be used. Further, an Fe-based microcrystalline film or a Co-based microcrystalline film may be used.

As a method of forming these metal magnetic films 3 and 4, any vacuum thin film forming technique represented by a vacuum deposition method, a sputtering method, an ion plating method, a cluster ion beam method, or the like is employed.

Further, the metallic magnetic films 3 and 4, the may be a single layer film of a ferromagnetic alloy material, for example SiO _2, T
A laminated film may be formed by laminating any number of layers via an intermediate layer of a ₂ O ₃ , ZrO ₂ , Si ₃ NO ₄ or the like.

In addition to the ferrite material, non-magnetic ferrite, zirconium oxide-based ceramic, crystallized glass, non-magnetic iron oxide-based ceramic, BaT
Titanate-based ceramics such as iO ₃ and K ₂ TiO ₃ are used.

In the magnetic head of the present embodiment, in particular, as shown in FIG. 2, a displacement G1 in the track width direction is applied to the butting position of the magnetic gap forming projections 24A of the magnetic core halves 5, 6. ing.

The deviation G1 is an angle formed between the center line F of the butting surface 8 of the magnetic gap forming projection 24A and the wall surface 10 of the track width regulating groove facing the same and the azimuth direction of the adjacent recording track TB. θ1 is shifted in a direction in which the angle θ is larger than the angle θ formed between the magnetic gap g and the azimuth direction of the adjacent recording track TB (the above-described “displacement of the magnetic gap in the positive direction”).

This is because, as shown in FIG. 4, the amount of the adjacent pattern signal picked up by the gap G1 of the magnetic gap strongly depends on the direction of the gap G1 of the magnetic gap. That is, the track width regulating groove 1 for regulating the track width Tw.
By forming the direction F of the bisector of the opening angle θ due to the deviation G1 of the magnetic gaps g of 0 and 11 away from the azimuth recording angle of the adjacent recording track, the azimuth recording of the adjacent recording track is performed. This is because there is no influence, and crosstalk from adjacent channels can be reduced.

Therefore, in the present embodiment, the track width T
The direction F of the bisector of the opening angle θ due to the deviation G1 of the magnetic gap g of the track width regulating grooves 10 and 11 for regulating w is formed in a direction away from the azimuth recording angle of an adjacent recording track.

Next, a method of manufacturing the magnetic head of the embodiment will be described.

First, as shown in FIG. 7, a substrate 21 made of a ferrite material is prepared. Then, the surface of the substrate 21 is set using a surface grinder.

In this embodiment, the substrate 21 is a single crystal or polycrystal of a magnetic ferrite material, a bonding material thereof, or a nonmagnetic ferrite, BaTiO ₃ , K ₂ TiO ₃ ,
Non-magnetic materials such as crystallized glass can be used.

The plane orientation of the single crystal ferrite used in the present embodiment is as shown in FIG. 7. However, single crystal substrates and polycrystal substrates having other plane orientations, and single crystal ferrite and polycrystal ferrite are used. May be used.

Next, as shown in FIG. 8, a winding groove 22 and a glass groove 2 are formed in the longitudinal direction of the substrate 21 by using a slicer.
3 are formed two by two. That is, the winding groove 22 and the glass groove 23 are formed symmetrically from the center of the substrate 21. By forming in this manner, a pair of magnetic core blocks 21a and 21b to be a pair of magnetic core halves 5 and 6 are formed from the one substrate 21 (see FIG. 13).

Next, as shown in FIG. 9, a track width regulating groove 24 is formed in a direction perpendicular to the winding groove 22 and the glass groove 23, that is, in the width direction of the substrate 21, using a slicer. When the track width regulating groove 24 is formed,
The positioning grooves 25 and 26 are formed to form the positioning projections 25A, 25B, 26A and 26B.

Here, these positioning projections 25 are used.
A, 25B, width H2 and positioning projections 26A, 2
The width H3 of 6B is different from the width of the abutment width. After the formation of the track width regulating grooves 24 and the positioning grooves 25 and 26, the surface of the substrate 21 is mirror-finished by polishing or the like.

In this regard, in the conventional track width regulating groove, the track width regulating groove is set at 30 ° with respect to the vertical direction of all the substrates.
And the track width regulating grooves are all formed to be uniform.

However, in this embodiment, both ends in the width direction L of the substrate 21 (shown by reference numerals “a” and “c” in FIG. 9).
The positioning grooves 25, 26 are formed so as to be adjacent to the track width regulating grooves 24, and the positioning projections 25A, 25B, 26A, 2 having different butting widths are formed.
After forming 6B, a track width regulating width 24 of 30 ° was formed in the remaining portion.

The alignment grooves 25 and 26 were formed so as to be perpendicular to the width direction L of the substrate 21.
That is, the positioning projections 25A, 25B, 26
A and 26B have both side surfaces substantially perpendicular to the track width regulating groove forming surface. By forming the positioning projections 25A, 25B, 26A, 26B in this manner, the substrates 21a, 21 serving as a pair of magnetic core halves are not affected by the formation angle of the track width regulating groove 24.
b is matched.

Here, the positioning projections 25A,
As shown in FIGS. 10 to 12, 25B, 26A, and 26B are the widths H of the protrusions 25A and 25B at the end of the substrate 21.
2 is 14.5 μm, and the width H3 of the protrusions 26A and 26B on the side adjacent to the track width regulating groove 24 is formed to be 13 μm. With this setting, the deviation amount δ of the magnetic gap in the track width direction is 1.5 μm,
A magnetic head having a track width Tw of 11.5 μm can be manufactured.

Further, the width H1 of the magnetic gap forming projection 24A formed between the track width regulating grooves 24 is formed so as to remain 13 μm like the width H3 of the projections 26A and 26B. Further, the inclination angle of the track width regulating groove 24 was formed so as to be 30 ° with respect to the vertical direction of the substrate 21. However, it goes without saying that the present invention is not limited to these.

In this embodiment, the positioning groove 2
5 and 26 are formed at both ends a and b of the substrate 21 in a shape perpendicular to the width direction L of the substrate 21. The shape of the alignment grooves 25 and 26 is, for example, V-shaped or the like. May be provided, and the position may be provided in another portion of the substrate 21.

Next, as shown in FIG.
1 is cut from the center thereof, and the cut substrates 21a, 2
1b is prepared.

Here, in the present embodiment, one substrate 2
1, since the positioning protrusions 25A, 25B, 26A and 26B having the above-described configuration are formed in addition to the winding groove 22 and the glass groove 23, the cutting is performed so that each of the positioning protrusions is symmetrical. 25A, 25B, 26A, and 26B are formed.

Next, the cut substrates 21a, 21
14B, a metal magnetic film 27 is formed by sputtering, and a gap film 28 is formed thereon, as shown in FIGS. When forming the metal magnetic film 27, as shown in FIG. 15, the film is formed including the inside of the track width regulating groove. In this embodiment, an Fe-Si-Ga-Ru alloy is used as the metal magnetic film 27.

Here, in order to improve the adhesion between the substrates 21a and 21b and the metal magnetic film 27, an oxide film such as SiO _2, Ta ₂ O ₅ , a nitride film such as Si ₃ O ₄ , or Cr,
A metal film of Al, Si, Pt or the like, an alloy film thereof, or a stacked film combining these may be used as a base film of the metal magnetic film 27. In the present embodiment, an SiO ₂ film having a thickness of 5 nm is used to improve the adhesive force.

Although the SiO ₂ single-layer film is used as the gap film, a two-layer film or a multilayer film provided with, for example, a Cr film as an upper layer may be used as a film for preventing the reaction with the fused glass 11. good.

Next, the substrates 21a and 21b produced as described above are heated to 500 to 700 ° C. while being pressed, and are joined with the low melting glass 14 as shown in FIG. Is prepared.

In this bonding, as shown in FIG. 17, the projections 25A and 26B having different widths H2 and H3 formed at both ends of the substrates 21a and 21b are combined with the positioning grooves 25 and 26. Matching was performed so that the straight portions S on one side coincided with each other. By abutting the different types of protrusions 25A and 26B in this manner, the amount of deviation δ of the magnetic gap in the track width direction is uniformly generated in order from the track width regulating groove 24 on the side adjacent to the positioning groove 26. However, it will be accurately butted. In the present embodiment, the shift amount δ of the magnetic gap in the track width direction is 1.5 μm as described above.

Next, after the joining substrate 30 is made to have a predetermined thickness by using a flat surface removing plate, a portion to be a sliding surface of the magnetic recording medium is subjected to cylindrical grinding.

Next, in order to secure contact with the magnetic recording medium on the sliding surface of the magnetic recording medium, as shown in FIG.
After performing the contact width processing and the processing of the winding groove 22 and the like,
As shown in FIG. 19, a large number of head chips 31 are manufactured by cutting out at the same angle as the target azimuth angle.

At the time of this cutting, the azimuth angle was made ± 20 °.
The azimuth angle was determined so that the magnetic gap in the direction was shifted. Thus, the magnetic head is completed as shown in FIG.

The deviation δ in the track width direction of the magnetic gap of the magnetic head manufactured as described above was measured.

As a result, when the gap abutting operation was performed in one direction only with the track width regulating groove of the conventional magnetic head, 3σ = 1.5 μm. The magnetic head has 3σ = 0.
A significant improvement of 7 μm was observed.

Embodiment 2 First, unlike the first embodiment, the magnetic head according to the present embodiment is configured such that the magnetic gap forming projections of the pair of magnetic core halves 5, 6 extend to both end edges. The magnetic head is completely matched.

However, in the method of manufacturing the magnetic head according to the second embodiment, as in the first embodiment, when the track width regulating groove 24 is formed, the positioning projection 36 is formed. This is common in that the positioning projections 36A and 36B are positioned.

As in the case of the first embodiment, the projecting portion 36 is formed so that the winding groove 22 and the glass groove 23
After the formation, the track width regulating groove 24 is formed when the track width regulating groove 24 is formed, as shown in FIGS.

That is, by forming the positioning groove 35 adjacent to the track width regulating groove 24 at both ends (indicated by reference numerals “a” and “c” in FIG. 20) of the magnetic core block in the width direction L. Then, the protrusions 36A and 36B are formed continuously to the magnetic gap forming protrusions 24A.

The positioning projections 36A, 36B
Are substantially perpendicular to the track width regulating groove forming surface.

The positioning protrusions 36A, 3
6B is formed on one substrate 21,
When the substrate 21 is cut from the center, the projections 3
6A and 36B have the same width H4.

Therefore, when the magnetic core blocks (substrates) to be a pair of magnetic core halves 5 and 6 are brought into contact with each other, as shown in FIG.
Abutting is performed such that the straight line portions S on one side of the both side surfaces of A and 36B coincide.

When butt is made in this way, the symmetrical positioning projections 36 (36A, 36B) are butt-butted, so that the magnetic gap g can be joined and integrated without causing displacement.

In the present embodiment, the protrusions 36A and 36B having the above-described structure are formed on both ends of the substrate 21, but they may be formed on other portions of the substrate 21. It is sufficient that at least one of 36A and 36B is formed.

In this regard, when the conventional track width regulating groove is formed, the track width regulating groove is formed in a direction perpendicular to all the substrates in order to increase the core sectional area near the magnetic gap and improve the recording / reproducing characteristics. The angle was set to 30 ° and the track width regulating grooves were all formed to be uniform. Therefore, when the magnetic core blocks (substrates) are butted against each other, as shown in FIG. 25, the work of matching the magnetic gap is performed only at the edges 101a and 101b of the track width regulating groove 101. For this reason, it is difficult to perform the matching so that the linear portions S coincide with each other, and the matching accuracy is not good.

On the other hand, in this embodiment, a pair of butting protrusions 36A and 36B having the same width are formed, and the butting protrusions 36A and 36B are formed.
Since the groove 35 continuous with B is formed perpendicularly to the substrate 21, high-precision butting can be performed without being affected by the angle of the track width regulating groove 24.
Therefore, a magnetic head capable of suppressing the influence of adjacent crosstalk can be reduced. The width of the pair of projections 36A and 36B is not limited to a specific value as long as they are the same because they are a pair.

Thereafter, as in the case of the first embodiment, cylindrical polishing or the like is performed, and then an azimuth angle is given to the magnetic gap.

The deviation δ in the track width direction of the magnetic gap of the magnetic head manufactured as described above was measured.

As a result, when the gap abutting operation was performed in one direction only with the track width regulating groove of the conventional magnetic head, 3σ = 1.5 μm. The magnetic head has 3σ = 0.
A significant improvement of 7 μm was observed.

As described above, the magnetic head manufactured as described above is a high-precision magnetic head capable of improving the error rate of the reproduced signal. Therefore, a home digital VTR
According to this method, a sufficient error rate can be obtained even during long-time recording, and it is expected that a Viterbi multifunction device, which is a circuit for improving the error rate by storing past determination conditions, is not required.

Although the specific embodiments to which the present invention is applied have been described, the present invention is not limited to the above-described embodiments, and various modifications can be made. For example, in the above example, a metal magnetic film is used as the main core, but a magnetic head in which a closed magnetic path is formed only by a ferrite core without forming such a film on the magnetic core substrate may be used. Needless to say, the same operation and effect as those of the above magnetic head can be obtained with this head. Further, a magnetic recording / reproducing apparatus using such a magnetic head can be applied to a digital signal storage device such as a data streamer in addition to a home digital VTR.

[0086]

According to the method of manufacturing a magnetic head of the present invention, when the track width regulating groove is formed, the positioning projections are formed so that both side surfaces are substantially perpendicular to the track width regulating groove forming surface. By aligning the alignment projections with each other, the magnetic gap forming projections of each magnetic core half are aligned with each other, so that the pair of magnetic cores is not affected by the formation angle of the track width regulating groove. A magnetic head is manufactured that has high abutting accuracy of the halves and can reduce the influence of adjacent crosstalk.

In the magnetic head manufactured in this manner, the error rate of the reproduction signal is improved, and high reliability is obtained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a state in which a magnetic head reproduces a recording pattern on a magnetic tape.

FIG. 2 is a schematic diagram showing a state in which a magnetic head reproduces a recording pattern of a magnetic tape when a deviation of a magnetic gap in a + direction occurs.

FIG. 3 is a schematic diagram illustrating a state in which a magnetic head reproduces a recording pattern of a magnetic tape when a magnetic gap in a negative direction is displaced;

FIG. 4 is a characteristic diagram showing a relationship between an error rate and C / N in the case of a deviation of a magnetic gap in a + direction.

FIG. 5 is a characteristic diagram showing a relationship between an error rate and C / N when a magnetic gap is shifted in a negative direction.

FIG. 6 is a perspective view showing an example of a magnetic head to which the present invention is applied.

FIG. 7 is a perspective view showing a manufacturing process of the magnetic head, and showing a process of making a substrate flat.

FIG. 8 is a perspective view illustrating a step of forming a winding groove and a glass groove in a substrate, illustrating a manufacturing process of the magnetic head.

FIG. 9 is a perspective view showing a manufacturing process of the magnetic head, showing a process of forming a track width regulating groove and a positioning projection on a substrate.

FIG. 10 is an enlarged perspective view of a part a in FIG. 9, showing an alignment groove.

FIG. 11 is an enlarged perspective view of a portion b in FIG. 9, illustrating a track width regulating groove.

FIG. 12 is an enlarged perspective view of a portion c in FIG. 9, showing an alignment groove.

FIG. 13 is a perspective view illustrating a step of cutting the substrate, illustrating a step of manufacturing the magnetic head.

FIG. 14 is a perspective view illustrating a process of manufacturing the magnetic head, and illustrating a process of forming a metal magnetic film.

15 is an enlarged perspective view of a portion d in FIG. 15, showing a state where a metal magnetic film is formed in a track width regulating groove and a gap portion.

FIG. 16 is a perspective view showing a process of manufacturing the magnetic head, and showing a state in which cut substrates are butted and joined.

FIG. 17 is a schematic diagram showing a manufacturing process of the magnetic head, and showing a process of adjusting and joining a direction in which a magnetic gap is shifted;

FIG. 18 is a perspective view showing a step of manufacturing the magnetic head, showing a step of cylindrically polishing the sliding surface of the magnetic recording medium.

FIG. 19 is a perspective view showing a step of manufacturing the magnetic head, and showing a step of cutting into head chips of a predetermined size.

FIG. 20 is a perspective view illustrating a process of manufacturing the magnetic head according to the second embodiment, and illustrating a process of forming a track width regulating groove and a positioning protrusion.

FIG. 21 is an enlarged perspective view of a part a of FIG. 20, showing an alignment groove.

FIG. 22 is an enlarged perspective view of a portion b in FIG. 20, showing a track width regulating groove.

FIG. 23 is an enlarged perspective view of a portion c in FIG. 20, showing an alignment groove.

FIG. 24 is a schematic diagram illustrating a manufacturing process of the magnetic head, and illustrating a process of abutting a magnetic gap without causing a displacement in a magnetic gap by a positioning projection.

FIG. 25 shows a process for manufacturing a conventional magnetic head.
It is a schematic diagram which shows the process of butting a pair of magnetic core blocks.

[Description of Signs] 1, 2, magnetic core substrate, 3, 4, 27 metal magnetic film,
5,6 magnetic core half, 7,8 gap forming surface, 9,
10, 11, 12, 24 track width regulating groove (side wall of track width regulating groove), 21 substrate, 21a, 21b magnetic core block (substrate), 24A magnetic gap forming projection, 25A, 25B, 26A, 26B, 36 , 36A,
36B Positioning projection, Tw track width, F
The center line between the butting surface of the magnetic gap forming protrusion and the wall surface of the track width regulating groove facing the same, the angle formed by the θ magnetic gap and the azimuth direction of the adjacent recording track, the butting of the θ1 magnetic gap forming protrusion The angle formed by the center line between the surface and the wall surface of the track width regulating groove opposed thereto and the azimuth direction of the adjacent recording track, the deviation amount of the δ magnetic gap in the track width direction, the width of the H1 magnetic gap forming protrusion, H2, H3 Width of alignment projection

Claims (3)

[Claims] A pair of magnetic core halves each having a track width regulating groove formed thereon and a magnetic gap forming projection formed thereon are joined and integrated so that the track width regulating groove forming surfaces face each other. A method for manufacturing a magnetic head, wherein a magnetic gap is formed between abutting surfaces of gap-forming projections, wherein both side surfaces are substantially perpendicular to the track width regulating groove forming surface when the track width regulating groove is formed. A method for manufacturing a magnetic head, comprising: forming protrusions; and aligning the positioning protrusions with each other to thereby align the magnetic gap forming protrusions of each magnetic core half. 2. A plurality of positioning projections having different butting widths are formed at a constant pitch, and the positioning projections having different butting widths are aligned.
2. The method of manufacturing a magnetic head according to claim 1, wherein a displacement corresponding to the difference in the width of the positioning projection is provided at the abutting position of the magnetic gap forming projection of each magnetic core half. 3. When giving an azimuth angle to a magnetic gap, a center line between an abutting surface of a projection for forming a magnetic gap, a wall surface of a track width regulating groove opposed thereto, and an azimuth direction of an adjacent recording track. 3. The method of manufacturing a magnetic head according to claim 2, wherein the misalignment is performed so that an angle between the magnetic gap and an azimuth direction of the adjacent recording track is larger than an angle between the magnetic gap and the azimuth direction of the adjacent recording track.